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General Industry 2015 Electric Safety


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This is the draft electrical presentation that I use in the OSHA 10 hour classes. I put it up here to give the reader an idea what I cover in the one hour.
I want to thank John Gryzwacz and Bob Lomastro for helping me with this presentation. They are the best electrical trainers in the country. Both teach the OSHA 3095 class at the OSHA ed centers.
Bob is at
John is
These presentation are always in continual improvement so I put a date on the draft. There are many earlier versions of this.

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General Industry 2015 Electric Safety

  1. 1. Industrial Electrical Safety John Newquist Draft 4 26 2015
  2. 2. Dec 2013
  3. 3. Oct 2013
  4. 4. June 2014 – Wet Location  42-year-old Lynden Endress was washing cattle on his farm.  That's when the power washer he was using short-circuited, electrocuting him.
  5. 5. November 2014 - Troubleshooting Dietrich believes the man was electrocuted by his wedding ring after it made contact with a copper wire in the back of the machine. Albert Washington, his brother-in-law, told officers that he turned the power off to the room. He asked for the power to be put back on to test the machine and then when a fault was noticed he tried to fix it without turning the electricity off again, at which point he was electrocuted, according to the Daily Mail.
  6. 6. March 2014 – Use as Approved
  7. 7. 1. Fall Protection in Construction (1926.501) 8,241 violations 2. Hazard Communication (1910.1200) 6,156 violations 3. Scaffolding in Construction (1926.451) 5,423 violations 4. Respiratory Protection (1910.134) 3,879 violations 5. Electrical – Wiring Methods (1910.305) 3,452 violations 6. Powered Industrial Trucks (1910.178) 3,340 violations 7. Ladders in Construction (1926.1053) 3,311 violations 8. Lockout/Tagout (1910.147) 3,254 violations 9. Electrical – General Requirements (1910.303) 2,745 violations 10. Machine Guarding (1910.212) 2,701 violations
  8. 8. Who needs training? 1910.332(a) Employees in occupations listed in Table S-4 face such a risk and are required to be trained. Other employees who also may reasonably be expected to face comparable risk of injury due to electric shock or other electrical hazards must also be trained.  At a minimum, be trained in and familiar with the following:  The skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment.  The skills and techniques necessary to determine the nominal voltage of exposed live parts, and  The clearance distances specified in 1910.333(c) and the corresponding voltages to which the qualified person will be exposed.
  9. 9. March 2015 • Issues?
  10. 10. Table S4 Typical Occupational Categories of Employees Facing a Higher Than Normal Risk of Electrical Accident  Blue collar supervisors  Electrical and electronic engineers  Electrical and electronic equipment assemblers  Electrical and electronic technicians  Electricians  Industrial machine operators  Material handling equipment operators  Mechanics and repairers  Painters  Riggers and roustabouts  Stationary engineers  Welders
  11. 11. Ohm’s Law The equations of Ohm’s Law are:  Voltage = Current times Resistance  Current equals Voltage divided by Resistance,  Resistance equals Voltage divided by Current.  13,800 Volts / 1000 Ohms = 13.8 Amps  480 Volts / 0.1 Ohms = 4,800 Amps  480 Volts / 0.01 Ohms = 48,000 Amps E I R
  12. 12. Determine the Current Voltage is 120 volts. Resistance is 12 ohms = amps. Voltage is 480, resistance is 1 Ohm = amps Voltage is 220 resistance is 2200 Ohm = amps
  13. 13. Electrical Current Effect 1 mA threshold for feeling 10-20 mA voluntary let-go of circuit impossible 25 mA onset of muscular contractions 50-200 mA ventricular fibrillation or cardiac arrest E. A. Lacy, Handbook of Electronic Safety Procedures, Prentice- Hall: Englewood Cliffs, New Jersey (1977)
  14. 14. Electricity and Conductors • Electricity (or more specifically current) does not flow to earth of ground, it flows from its voltage source back to its voltage source. – John Gryzwacz • Electricity flows through conductors • Water, Metal, the human body can be conductors • Insulators are not conductors
  15. 15. Ventricular Fibrillation When the heart is in ventricular fibrillation, the musculature of the ventricles undergoes irregular, uncoordinated twitching resulting in no net blood flow. The condition proves fatal if not corrected in a very short space of time. Normal
  16. 16. National Electric Code  The National Fire Protection Code, got its first electrical section in 1897  Concern about many electrical fires and conflicting codes
  17. 17. Knob & Tube 1881 NY Board of fire underwriters: When it becomes necessary to carry wires through partitions and floors, they must be secured against contact with metal, or other conducting substance, in a manner approved by the Inspector of the Board.
  18. 18. Electrical Grounding  1928 NEC "Grounding required in conductive locations such as in basements or in walls containing metal lath, even if the equipment was fed by Knob and Tube wiring, nonmetallic cable lacking a grounding conductor.  Current travels both paths. Grounding involves providing a conductor to carry most of the current into the ground rather than into a body.
  19. 19. 120 Volts on the body • Current = Volts/Resistance • If you are sweaty and barefoot, then your resistance to ground might be as low as 1000 ohms. Then the current would be: • I = 120 V/1000 ohm or 120 mA – ventricular fibrillation • “The fact is in the US there are more electrocutions annually at 120 volts than any other voltage.” – John Gryzwacz
  20. 20. Equipment Grounding • 1928 NEC "Grounding required in conductive locations • How does it work? • The equipment grounding conductor provides a safe path for the fatal fault current to flow back to its source and instantaneously trip the circuit protection device (circuit breaker or fuse). – Gryzwacz • Current travels both paths. • Grounding involves providing a conductortocarrymostofthe currentintothegroundratherthan intoabody. -BobLomastro •What’s its function or purpose? • To prevent electrocution in the event of a short circuit or fault in the tool or equipment.
  21. 21. The GFCI operates by sensing the difference between the currents in the Hot (ungrounded) and Neutral (grounded) conductors. Under normal conditions, these should be equal. The GFCI will shut off at 5 mA in 1/40th of a second. Imagecourtesy of Bob Lomastro
  22. 22. GFCI’s –1971 NEC
  23. 23. Electrocution Deaths by Age Group •244 Victims In The Study N u m b e r NIOSH Fatality Assessment Control Evaluation (FACE)
  24. 24. Double Insulated  Insulated from shock  Square with square  Watch out for no lab testing (NRTL) Bottom two images courtesy of
  25. 25. Power Taps • 29 CFR 1910.305(g)(1)(iii) reads as follows: • "Unless specifically permitted in paragraph (g)(1)(i) of this section, flexible cords and cables may not be used: • (A) As a substitute for the fixed wiring of a structure.
  26. 26. Fluorescent Lighting Most common cause of electrocution among electricians - Changing ballast while live. Workers not de-energizing circuit nor wearing any PPE
  27. 27.  Shall be de-energized before the employee works on or near them, unless the employer can demonstrate that de-energizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations.  Testing live to find fault or short is common reason. Working Live Insulated leads alones are not safe. Wear rated gloves when testing.
  28. 28. #1 - Boxes with unused openings Knockout Missing 1910.305(b)(1) Note: Circuit breakers are designed to protect property not people. Missing Dead Fronts
  29. 29. #2 – Exposed live parts over 50 Volts 1910.303(g)(2)(i) Exposed wiring - missing electrical housing
  30. 30. #3 – Missing covers 1910.305(b)(2)
  31. 31. #4 - Hanging pendant boxes 1910.305(g)(1)(iii) Box has strain relief and no knockouts Knockouts can get pushed into box Impro per strain relief
  32. 32. #5 — Missing Grounding Conductor 1910.304(f)(4)
  33. 33. #6 – Disconnects not labeled Label is tattered No labels on disconnects 1910.303(f)
  34. 34. #7 – Strain relief Wire pulled out of shredder 1910.305(g)(2)(iii) Missing on strain relief
  35. 35. #8 – Equipment not used per listing Receptacle box not mountedBox used as an extension cord 1910.303(b)(2)
  36. 36. Nov 2013  Citation 2 Item 1 Type of Violation: Willful  29 CFR 1910.303(b)(2): Listed or labeled electrical equipment was not used or installed in accordance with instructions included in the listing or labeling:  On or about May 24, 2013, and at times prior thereto, Spiral "final" department, employees are allowed to use foreign material to operate control panels.  Employees are using makeshift instruments, including but not limited to clip binders and welding wire bent in the shape of shepherd's hooks to override the "forward" limit switch on the pipe conveyor console panel, so that the pipe can continue horizontally down the conveyor and the incoming pipe can immediately be worked on to reduce workload buildup.  The practice of overriding the limit switch on the console panel exposes employee(s) to hazards associated with being struck by and caught-in between conveyed piping, stopping blocks and other stationary or transported objects.
  37. 37. #9 – 3’ Clear spaces Storage in front of panel box 1910.303(g)(1)(ii) Panel box blocked
  38. 38. #10 – Electrical Free of Hazards 1910.303(b)(1) Ground prong stuck in receptacle Open wiring spliced out of box
  39. 39. #9 – 3’ Clear spaces • 1910.303(g)(1)(ii) Panel box blocked Storage in front of panel box
  40. 40. Receptacles Receptacles will have hot, neutral, and a grounding conductor
  41. 41. Insulated Gloves  Electrical gloves can protect the worker who must test circuits live.  Gloves can be bought for work with voltages under 500 volts. These are Class 00 gloves.  Gloves must be sized for each employee.  Test every six months.
  42. 42. Voltage Detectors • “Senses the steady state electrostatic field produced by AC voltage through insulation without requiring contact to the bare conductor. • A red glow at the tip and a beeping noise (if not switched OFF) indicates the presence of voltage.” - FLUKE The detector will not work on dc Workers must test for the absence of voltage.
  43. 43. AC Voltage Detectors Source: Fluke Read the safety limitations from the tester mfr
  44. 44. •Worker died when shocked pulling out barrel fuse with pliers •Electrical circuits must be locked out before doing any work on the circuits if possible. Fuse Pulling
  45. 45. Outdoor signs Worker found unconscious taking out electric receptacle while still energized. Breakers were not locked out. No labels in panel
  46. 46. Air Handlers Worker touched an energized horizontal heating coil
  47. 47. Daily Checks  Cord and plug connected equipment should be check daily before use.  1910.334(a)(2)(i)  Portable cord and plug connected equipment and flexible cord sets (extension cords) shall be visually inspected before use on any shift for external defects
  48. 48.  For example, if an internal fault should occur in the wiring as shown in the figure below, the equipment would not stop when the switch is released or would start as soon as a person plugs the supply cord into the improperly wired outlet. This could result in serious injury. Reverse Polarity On October 30, 2004, Employee #1 was apparently trying to use a portable electric grinder at a work site when he was electrocuted from ungrounded and reverse polarity electrical sources.
  49. 49. Capacitors Pleasant Prairie WI OSHA’s investigation found the temp worker had inadvertent contact with electrical equipment while trouble- shooting an electrical failure on a heat- sealing machine. Company failed to require personal protective equipment for employees working near exposed, energized electrical parts. The company also did not develop procedures to de-energize circuits and equipment safely or ensure stored energy capacitors were grounded. Capacitors store electricity indefinitely. They must be properly
  50. 50. Clear Space again 1926.403(i)(1) Sufficient access and working space shall be provided and maintained about all electric equipment to permit ready and safe operation and maintenance of such equipment.
  51. 51. Classified Locations Combustible dust & exposed wiring.
  52. 52. 1. What mA typically causes muscle contractions? _____ 2. A GFCI will shut off in _____ of a second. 3. When the musculature of the ventricles undergoes irregular, uncoordinated twitching resulting in no net blood flow is called ________ ________. 4. Live parts over ____ volts need to be guarded. 5. ____ feet of clear space must be maintained in front of electrical panels. Quiz
  54. 54. Electrical Statistics • As many as 80 percent of all electrical injuries are from an arc-flash contact and ignition of flammable clothing. • 2,000 people are admitted to burn centers • Source: Cooper Bussmann
  55. 55. Arc Flash Incidents  Estimated 5-10 arc flash incidents per day  Numerous fatalities per year  Estimates as to costs of burn injury medical (skin grafts, therapy )and related costs (replacement worker, rehabilitation,) average between 1.0 and 4 million dollars.  And then we have a social cost!!!
  56. 56. Now which of you has seen this label?
  57. 57. The NEC 110.16, which reads: "Flash Protection. Switchboards, panel boards, industrial control panels, meter socket enclosures, and motor control centers in other than dwelling occupancies, which are likely to require examination, adjustment, servicing, or maintenance while energized, shall be field marked to warn qualified persons of potential electric arc flash hazards*. The marking shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing, or maintenance of the equipment." Field Marking
  58. 58. An arc flash is a short circuit through the air The temperature of an arc can reach approximately 35,000 degrees Fahrenheit or about four times as hot as the
  59. 59. If the marking is not there. • The system was turned over without the appropriate hazard warnings. • It is not in compliance with the 2002 – 2014 National Electrical Code • Article 90 in the NEC specifically states that this code is not an instruction manual for the untrained/unqualified persons (it’s for trained qualified workers). - Gryzwacz • If we need to label equipment to inform alleged “qualified” workers of the hazards of electricity (including arc flash/arc blast) then perhaps they shouldn’t be considered to be qualified.
  60. 60. Common Causes of Electric Arcs  Dust and impurities  Corrosion  Condensation of vapor and water dripping  Accidental touching phase to phase or phase to ground  Dropping conductive tools  Over-voltage across narrow gaps  Failure of insulating materials  Improperly designed or utilized equipment  Improper work procedures
  61. 61. An arc flash is a short circuit through the air The temperature of an arc can reach approximately 35,000 degrees Fahrenheit or about four times as hot as the surface of the sun.
  62. 62. Electrical Processes Causing Flashes  Removing or installing circuit breakers or fuses  Voltage testing  Working on control circuits when energized parts exposed  Applying safety grounds  Racking circuit breakers  Racking starters  Removing bolted covers
  63. 63. Arc Rated PPE
  64. 64. NFPA 70E Provides additional guidance to determine Arc Flash Assessments and clothing requirements.
  65. 65. PPE Categories PPE will depend on which boundary and task you are in. FR clothing must be work first at Category 1 work. Also FR clothing is not permitted for arc flash/arc blast hazard protection, the clothing must be “arc rated (per ASTM).
  66. 66. Power Lines 10 foot safe clearance up to 50,000 volts. Avoid storing material under the lines. Scaffold hits power lines video
  67. 67. Summary Grounding involves providing a conductor to carry most of the current into the ground rather than into a body.
  68. 68. •Summary Water and otherliquids are good conductors of electricity.
  69. 69. Lastly A three-pronged plug should never be used in a two pronged outlet
  70. 70. •Questions? This is very unsafe!
  71. 71. Background • Classes: OSHA 10/30 Hour, Incident Investigation, Confined Space, Excavation Safety, Cranes Signaling and Rigging, Fall Protection, Scaffold Safety, and many more • 2170 Trained in 2014!! 71 • 34 years working with top companies to achieve ZERO injuries • Certified Safety Professional • OSHA 1983-2012 • Founding Member of ANSI Z359 • 815-354-6853 • Services: Mentoring safety professionals in hazard recognition and auditing, Site Safety Audits, Custom Training, OSHA Litigation Consultation, Expert Witness,